I can't really say about your location however IMO you should switch over to PVC and get rid of bell boxes to neaten up a bit.

The other issue I belive that when someone install them they were not really watching the gasket when they install the luminaires. which that is pretty common failure if not installed properly or gasket get dry or get brittle and let water seep in.

Drill the glass bottom IMO it can be done otherwise lexan verison is easier to drill out { but watch the wattage rating on them }

So there are few ways you can do this the key issue is find a way to prevent any more water pentration and have proper drain fitting or drill the drain opening as need to.

IMHO, water is going to find any point of entry into these fixtures, no matter what you do from what I can see in the pics. The 'raintite' EMT connectors are raintite....not waterproof.

Judging from the pic, that water did not enter quickly, as it is dirty/discolored.

You may achieve a 'better' install by having conduits enter the fixture base box directly, as opposed to the top entry.

I came accross some classified location (explosion proof) fixtures that were submerged in a wet well pump station (sewage) that were half full of liquids; that seeped in via the threaded (min 5 threads) and the fixture bodies. Water finds a path!!

The space fillers in the box are also not vapour or water proof. the back box can allow water in via the hub where the emt and connector screw into the box.If not located in a hazardous location a small hole big enoug to let water out and ants in can work for condensation.Drilling holes in glass is a bugbear and don't bother if the glass is tempered. it will just break if you drill.

There are replacement globes available - they're pretty interchangeable between brands, unless you get the $8 box store specials - and some are even made from plastic.

This is worth noting, because many are of tempered glass, and those will instantly shatter into glass 'gravel' the instant your drill bit pierces them. DON'T DRILL GLASS.

In a location like this one, you're in a no-win situation. Add a drain hole, and the thing fills up with gnats.

Your best solution might be to completely do away with the globe, but keep the cage. Then, use a bulb that is outdoor rated. Outdoor-rated PAR bulbs are common, and the 'halogen' bulbs have a heavy enough glass that they just might work. The cage will just help keep flammables (like leaves) from touching the hot bulb. There might even be outdoor-rated CFL's.